Many internal structures refer to trace positions; this is an important type of values. In the code, it is sometimes `u32`, sometimes `usize`. While such variables usually have "_pos" suffix, having a dedicated type does improve code with type guarantees.
As `wasm32-wasi` target doesn't seem to support sanitizers, we are to
execute tests with native code. The feature `test_with_native_code` is
introduced for that.
Closes#247.
Use pooled `avm::server::AVMRunner` instances of
air_iterpreter_server.wasm to reduce tests' running time. It avoids
repeated WASM loading and compilation.
On my hardware, `cargo test --release` execution time (precompiled)
decreases from almost 6 minutes to 1.5 minutes.
